DIY LEDs - The write-up

[TheFishMan65]

Quick opinion:
about 100-120 LEDs. 40 CW 80 RB, you can mix this with blue, neutrals, warm, but that is the general mix.
I would go with Cree's. Mixed reading on Stieve's.
You want the dimmable IMHO so you can acclimate your coral. Maybe 6 or 80 degree optics.

 

[bhammer]

I'm no expert but I'd just use the U-channel without the sheet. I used 5 72" u-channel rails to make my fixture. It is incredibly simple and works like a champ. Applying gentle airflow across the rails really cools them down nicely.

Thanks for the feedback.

I just did a build using u channel and an aluminum plate. Since the dissipation of heat is effected by the surface area of the heatsink, the more surface area the better cooling effect, I figured that adding an aluminum plate to the bottom would increase my surface area and improve cooling.

Mine is a 18x18 heatsink with 72 LED's and no fan (yet), with all of the LED's running at 100% the heatsink only gets to right around 100 degrees. It is warm to the touch, but only a few degrees warmer than commercial fixtures. I may add a fan, but I don't think it is required.

I am thinking about setting up a small test maybe 6 LEDs, of not mounted and run for an hour and then put it on a plate and run again to see if there is a difference. In looking at many of the threads, I am thinking to save money and not mount to a sheet of almn.

 

[bhammer]

I can see where doing a sheet of aluminum and U channels adds some surface are for heat dissipation. However, is see a few drawbacks, it means two layers of thermal paste and unless you are using really thick plate I am not sure it will stay tight in the middle with only the ends bolted together. Also the plate does not allow the air to flow as smoothly (no air flow in the center).

I think you would be better off with just the channel, but maybe someone that does this for a living can chime in.

That is a good point but had thought of. If I do it, I'll use or make some thermal epoxy to use. The issue with most of the thermal epoxy I have found requires an external heat source for a full cure. I have found some that doesn't require heat for a cure but their temp range seems low.

On a couple sites I visited, there were some recepies for home made thermal epoy with pretty good full test results.

Looking at most posts, I may just skip using the plate as people seem to be keeping their LEDs cool enough.

 

[signal7]

Thanks for the feedback.

I am thinking about setting up a small test maybe 6 LEDs, of not mounted and run for an hour and then put it on a plate and run again to see if there is a difference. In looking at many of the threads, I am thinking to save money and not mount to a sheet of almn.

I think it would also be best for heat dissipation to have the LED's mounted directly to the u-channel, not to mention the airflow around the rails would be better without the sheet. Can't hurt to experiment a little though.

If you're looking for that extra cooling feature, I think your time/money would be better spent on small heatsinks applied inside the u-channel on the opposite of each LED. I can say that with a few fans my rails are cool to the touch, so I don't think this is necessary.

 

[madbomber]

I checked the latest summary on paga 171 and cannot find out how most people are dimming these builds with controllers. I want to control a setup with an Apex. How can I find the resources to do this. Any links are appreciated.

Thx

 

[bhammer]

I checked the latest summary on paga 171 and cannot find out how most people are dimming these builds with controllers. I want to control a setup with an Apex. How can I find the resources to do this. Any links are appreciated.

Thx

There are lots of posts talking about dimming with an APEX. You will need a CAT 5 cable. The wiring diagrams are on this thread along with over in the Neptune forum. Each apex port has two dimming channels so you can dim 4 channels total with the base unit. Some have added 5 drivers to the same dimming channel without issue. What drivers are you planning to use?

 

[bhammer]

I think it would also be best for heat dissipation to have the LED's mounted directly to the u-channel, not to mention the airflow around the rails would be better without the sheet. Can't hurt to experiment a little though.

If you're looking for that extra cooling feature, I think your time/money would be better spent on small heatsinks applied inside the u-channel on the opposite of each LED. I can say that with a few fans my rails are cool to the touch, so I don't think this is necessary.

I am looking at a 230+ LED build so the heatsinks are out of the question. :spin1:

I think I will try the two ways just so I can see. Heck, that will probably my only true contribution to this thread.

 

[madbomber]

bhammer, you forgot the thread link. I plan on using meanwell I guess. Though I am not certain yet. I need to research more.

 

[bhammer]

bhammer, you forgot the thread link. I plan on using meanwell I guess. Though I am not certain yet. I need to research more.

I was meaning this thread that we are in now and responding too .... Here is the link and I would start reading. :eek1:

Yup, the summary is a great place to go back to but I would suggest that you start at thread #1 and read.... You will pick up a lot doing this and many of your questions will be answered.

There are many Meanwell choices. Most pepole here use the ELN if they only need a couple drviers and the HLG if they need more. But, I personally think that you need to define how many LEDs you need / want and that will really drive what model of driver you will be using for your build. Then, you can fine tune your LEDs based on the selected drivers to match voltage and current requirements.


I will have 3 different models based on my needs and sizing.

 

[jkopp36]

Ok, I've been reading all this a lot and think I have a better grasp on how to match drivers to LEDs. To be sure, is this correct?:

I could run 96 XP-E RB LED's at 750mA with either a pair of HLG-120-54's or one HLG-240-54 but I will only be able to dim the 240 to 50% where as the 120 will go all the way dim.

-and-

I could run 48 XP-G CW LED's at 1050mA with either a HLG-185-54B on three strings of 16 or a HLG-185-42B on four strings of 12.

I'm also hoping for a little input:
I'm planning a build to go over my SPS dominant 225g in-wall tank. Dimensions of the tank are 72"Lx30"Wx24"T. There is 3" eurobracing and about a 12" wide glass center brace. It is currently lit by 3 400W Radiums and a pair of VHO Super Actinics. The above LED counts are what I am thinking (144 total - 96RB/48CW) but would welcome alternative opinions and some input on how to arrange them. My idea is six rails with 24 LEDs on each. I'm open to any and all suggestions and realize I may be low on LED count. I already have 36 each of the above mentioned LED's but would be willing to sell and get others if it's worth it. I also really have no idea where to start on optics. I can put the LED's pretty much any hieght up to about 20" above the water line and the higher the better as far as ease of access.

Thanks in advance. You guys always have great input!

 

[brassmonkyballs]

Ok, I've been reading all this a lot and think I have a better grasp on how to match drivers to LEDs. To be sure, is this correct?:

I could run 96 XP-E RB LED's at 750mA with either a pair of HLG-120-54's or one HLG-240-54 but I will only be able to dim the 240 to 50% where as the 120 will go all the way dim.

-and-

I could run 48 XP-G CW LED's at 1050mA with either a HLG-185-54B on three strings of 16 or a HLG-185-42B on four strings of 12.

I'm also hoping for a little input:
I'm planning a build to go over my SPS dominant 225g in-wall tank. Dimensions of the tank are 72"Lx30"Wx24"T. There is 3" eurobracing and about a 12" wide glass center brace. It is currently lit by 3 400W Radiums and a pair of VHO Super Actinics. The above LED counts are what I am thinking (144 total - 96RB/48CW) but would welcome alternative opinions and some input on how to arrange them. My idea is six rails with 24 LEDs on each. I'm open to any and all suggestions and realize I may be low on LED count. I already have 36 each of the above mentioned LED's but would be willing to sell and get others if it's worth it. I also really have no idea where to start on optics. I can put the LED's pretty much any hieght up to about 20" above the water line and the higher the better as far as ease of access.

Thanks in advance. You guys always have great input!

Actually i think your LED count is spot on and I'm using the same ratio as you RB to W...although 25% of my whites are NW & 75% CW. If you have center braces i suggest you look at doing pendants on each side.

Optics...thats a whole other topic but based on recent discussions its safe to say 60 degree optics will require you going up to around 14" depending on the look you are trying to achieve. For example my fixture at 8" with 60 degree lenses gives a super dramatic look but the edges of the tank are now very dim. Although i really really like it I'm going to switch out to 90 degree simply because I plan to add a whole lot more coral and want to utilize all the rock work on each end as well as the sand.

I'm sure you will get some more responses as well. Good luck and post the results!

 

[TheHoove]

Optics...thats a whole other topic but based on recent discussions its safe to say 60 degree optics will require you going up to around 14" depending on the look you are trying to achieve. For example my fixture at 8" with 60 degree lenses gives a super dramatic look but the edges of the tank are now very dim. Although i really really like it I'm going to switch out to 90 degree simply because I plan to add a whole lot more coral and want to utilize all the rock work on each end as well as the sand.

!

Tonight I added 60 degree optics to all but 10 odd colors of my LEDs. Mine are 40" wide over a 48" tank. At 9" above the water, I really like the look. My ends of the tank are only slightly dim. But it helped with shadows. And I didn't notice much change in terms of color mixing. So I'm very happy.

 

[brassmonkyballs]

Tonight I added 60 degree optics to all but 10 odd colors of my LEDs. Mine are 40" wide over a 48" tank. At 9" above the water, I really like the look. My ends of the tank are only slightly dim. But it helped with shadows. And I didn't notice much change in terms of color mixing. So I'm very happy.

Yeah thats the other thing...my 36" heatsink vs your 40"...if i were doing it over I would have perhaps gone 42" had I thought about the 60 degree optics.

 

[TheHoove]

I was mostly worried about banding going to the optics, since mine is in rows of color. But its not noticable. But i did end up with a couple odd spots where the blue is really powerfull on the sand and white rocks. Its like a bright blue spot here and there. Its there with and without the optics. I cant even pinpoint what leds its from. But it doesent bother me anyways.

 

[wilkerschnepf]

Ok time to ask the experts. I am starting my led design, and need some help with driver selection and wiring.

Here is my basic layout:

I would like to use two dimable drivers for blue/royal blue and warm white/cool white. I am using satis leds all are 3.2-3.7V 750ma. I know these are not the most efficient, it is just a "practice" fixture for me. I was wondering if 2 of the MW-60-48D can be wired to run my setup. I can add or remove some leds if needed i have plenty of extra leds to play with.

I was thinking two parallel strings of 11 or 12 leds on each driver.

 

[TheFishMan65]

As long as each string as the same types and counts of LEDs you should be fine. See JP thread for a good description on parallel builds.

 

[porksmash]

As long as each string as the same types and counts of LEDs you should be fine. See JP thread for a good description on parallel builds.

Can you link this thread? I'm sure I'm not the only one who doesn't know what JP means.

 

[TheFishMan65]

Actaully I think that was the wrong one. Try this [katchupoy's one] one.

If I am mistaken and it does not do parallel builds (still a good read for someone starting out) let me know here and I will try again. I follow about 150 LED thread and I often get them mixed up.

 

[sea of cortez]

Try these 2 (both are full of parallel info)
http://www.reefcentral.com/forums/showthread.php?t=1751598 KRESS's
http://www.reefcentral.com/forums/showthread.php?t=1973462&page=3 JP's

 

[wilkerschnepf]

JP's Thread was a great read. I just searched JP LED and it was the second or third result. Great pictures to follow along with great support from kcress. Didn't go into detail on calculations for number of leds in parallel strings. But he did use two parallel string just like i will be with similar amounts of leds.

Thanks for the tip and all you guys have done to make DIY LEDS possible. Once i get started on my build i will make a thread, but i am still a couple weeks away from that.

Cheers!